A new species of giant raptor has been discovered in the Hell Creek Formation in South Dakota. The research team was led by a University of Kansas alumnus. The 17 feet (5.1 meters) long raptor has been named Dakotaraptor (Dakotaraptor steini).

The fossil had evidence of quill knobs (ulnar papilli) where feathers would likely have been attached to the forearm of the dinosaur. The feathers are shown in the artist's interpretation by Emily Willoughby above.

KU Paleontologist and co-author David Burnham, says in a statement, "This new predatory dinosaur also fills the body size gap between smaller theropods and large tyrannosaurs that lived at this time."

Robert DePalma, curator of vertebrate paleontology at the Palm Beach Museum of Natural History and lead author of the research, says, "This Cretaceous period raptor would have been lightly built and probably just as agile as the vicious smaller theropods, such as the Velociraptor."

The image below shows a size comparison between Dakotaraptor, a man and Achillobator.

A research paper on the giant raptor was published here in the journal, Paleontological Contributions.